5 signs your TMT bar supplier isn't testing every batch

A mill test certificate (MTC) is the single easiest way to check whether a supplier is actually testing what they ship. If a supplier can't produce one per batch, on request, that's the first sign.

Second: the certificate should show actual measured values — yield stress, tensile strength, elongation, chemical composition — not just a grade name. 'Fe 550 compliant' without numbers tells you nothing.

Third: ask when the batch was tested relative to when it was rolled. A same-day or next-day test date suggests in-house testing; a certificate dated weeks later, or from a generic third-party lab with no batch traceability, is a warning sign.

Fourth: weight-per-metre should be checked, not assumed. A bar that's rolled light of spec still passes a visual inspection but under-delivers on-site.

Fifth, and simplest: ask to see the lab. A supplier confident in their testing will show you the Universal Testing Machine and spectrometer readings for the batch you're buying.